3D Printing Helps Cal Poly Supermileage Club Make 1500 MPG Possible

Each year, Shell Oil Company sponsors the Shell EcoMarathon competition, a fuel-efficiency competition where around 30 teams compete to build a vehicle that uses the least amount of gas to go a specified distance. The Shell EcoMarathon competition provides engineering and technology students with a challenging design project that involves the development and construction of a single-person, vehicle designed for optimal fuel consumption. Teams are required to start with a one cylinder lawnmower engine and make decisions on significant modifications to meet their goals. There are two divisions in the challenge, Collegiate and High School.

The Cal-Poly Vehicle

California Polytechnic State University in San Luis Obispo, California, has an award winning supermileage club comprised of design and engineering students attending the learn by doing centered University. For the 2017 competition, the team placed 4th, out of 1,500 with a vehicle that achieved over 1,500 miles per gallon. As they head into the design and iteration phase for the 2018 competition the Cal Poly team’s main focus is end-to-end designs transferred to the club from previous generations of performance testing and competition.

Redesign With The Future In Mind

“Essentially what we do, is kind of like what Apple does with the iPhone 6 vs. the iPhone 6S, where it’s basically the same chassis of the model, but the interior of it is remodeled to make it faster and more efficient. That’s kind of how Supermileage operates, because making a chassis is extremely expensive, there’s a lot of analysis, and material, like carbon fiber that go into it; and of course a lot of man hours.” Weston Andrew Cramer, third year member of the team said. “So, last year, we took the chassis and redesigned it to absorb more shock and duress in general. Then, we took a look at the interior and updated the look and some of the safety elements as well. Basically every part inside the car was revamped.”

Two of the major changes to the design of the interior of the vehicle that had major impacts to the construction and safety were the decision to take the breaking mechanism in the vehicle from a hand to a foot brake, and 3D printing the steering wheel in the Ultem material. The team leveraged the strength to weigh benefits of FDM materials. “With FDM prints being strong in plane, instead of a more detail oriented isotropic material, like the with the polyjet, ” said Eli Rogers, now a Cal Poly Supermileage Alumni, working professionally in 3D printing since graduation. The Superileage experience has been a rewarding one for Eli, one where the impacts have been felt in his day to day work 3D printing designs for customers, “At the club level, we do so much work that you don’t get to experience in the classroom, work that prepares you for a job that has stresses like a situation where the customer doesn’t know the answer, and you are tasked, as the engineer on the job, to find the answer with the best possible outcome for the customer.”